The present invention relates generally to the conversion of uranium oxides to uranium metal, and more particularly to a method for economically converting uranium oxides to metal while eliminating the explosive and environmentally unsafe conditions associated with oxide reduction techniques heretofore utilized.
Scrap and waste uranium metal usually undergoes oxidation during the storage thereof. The conversion of such uranium oxides to uranium metal for use in various applications has been commonly achieved in a bomb-type reduction process in which the oxides are first hydrofluorinated to uranium tetrafluoride. A reducing agent such as metallic calcium, magnesium, or lithium, and various chemical igniters are loaded into a reaction vessel together with the uranium tetrafluoride and heated to the desired ignition point to convert the uranium tetrafluoride to uranium metal. The resulting uranium metal is in the form of a regulus which is separated from the calcium fluoride slag for use in the desired application. While this reduction reaction provides high purity uranium metal there are some shortcomings which detract from the overall process. For example, the reaction produces a uranium-containing by-product of fluorides from the reducing agents. Further, some crucible material is taken up in the reaction and must be processed with the fluorides through various dissolution and solvent extraction steps to recover any residual uranium remaining in the by-products. These uranium metal recovery steps are fairly complicated and expensive and also present serious environmental and industrial safety problems due to the required use of hydrogen fluoride and the potential explosive conditions associated with the process.